Pressure operated chemical injector



Aug. 17, 1965 J. H. WATTS PRESSRE OPERATED CHEMICAL INJECTOR Filed July 25, 1962 2 Sheets-Sheet 1 Jo/m Henry Was 1N VEN TOR.

Aug 17 1965 J. H. wATTs 3,200,840

PRESSURE OPERA'IED CHEMICAL INJECTOR Filed July 25, 1962 2 Sheets-Sheet 2 s q) H v k gi x n r u) l xx: r v`- l 0 `I`Q r r i I Q\ f v u" j Q 1 Q E f I l//f N All o l /X John Henry Wafs INVENTOR. N 9 i BY @Mm LL WMMW United States Patent O 3,2tltl49 PRESSURE PERATED CHEMlCAL NJECTOR .lohn Henry Watts, Rte. 4, Canton, Ga. Filed July 25, 1962, Ser. No. 212,336 4 Claims. (Cl. 137-56415) The present invention generally relates to chemical injectors, and more particularly to a pressure responsive injector easily incorporated into a conventional boiler system for operation in response to the pumped liquid being introduced into the boiler.

One of the primary objects of the present invention is the provision of a means for effectively and automatically injecting a predetermined amount of material into a liquid flow.

Another .object of the present invention resides in the provision of an easily installed means for injecting a chemical, such as for example various types of rust inhibitors, into the flow of water from the boiler pump to the boiler.

Another object of the present invention resides in the provision of a chemical injector responsive to the flow of Water from the boiler pump.

Another object of the present invention resides in the provision of a chemical injector as in the above object wherein the injector is automatically lilled upon a stopping of the boiler pump.

Another object of the present invention resides in the provision of a relatively simple pressure operated chemical injector which requires 4a minimum amount of parts and no complicated valve mechanisms thereby reducing the maintenance required to a basic minimum.

Another object of the present invention resides in the provision of a means for adjusting the amount of material injected by the device of the present invention.

These together with other objects and advantages which will become subsequently apparent reside in the details or" construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE l illustrates the injector of the present invention in its return or chemical receiving position, portions being broken .away for purposes of clarification;

FGURE 2 is a view similar to FIGURE l however illustrating the device in its forward or discharging position;

FIGURE 3 is a cross sectional view taken substantially upon a plane passing along line 3 3 in FIGURE l; and

FIGURE 4 is a cross sectional view taken substantially on a plane passing along line 4 4 in FIGURE. l.

Referring now more particularly to the drawings, reference numeral l designates a conventional wa'ter feed line extending from a boiler pump (not illustrated) and including a one-way check valve 12 for preventing backow in an obvious manner.

The device 14 of the present invention is intended to be operatively interconnected with the feed line and responsive to the water pressure therein induced by the periodic running of the boiler pump. This device 115i consists basically of three axially aligned and interconnected piston and cylinder assemblies 16, 13 and 2li. The first piston and cylinder arrangement 16 consists of an enlarged hollow cylinder 22 having the rear end thereof peripherally received within an annular groove 24 in the inner face of the rear end plate 26. The front of the cylinder 22 is similarly received within the groove 28 of the intermediate plate 30 which is of the same size as plate 26.

The piston 32 in the rst assembly 16 is threadedly received on the rod 34 and secured thereto by a suitable 3,2%,840 Patented Aug. 17, i965 lock means 36. The front end of the rod 34 extends through the intermediate plate 3d and is lixedly secured both to the piston 3S and the rod d0, a suitable lock nut 42 being provided. The piston 32, as will be appreciated from the drawings, is smaller than the piston 32 and includes sealing means 44 and i6 `on both sides thereof contrary to one sealing means 48 on the first piston 32. The cylinder 5@ of the second assembly i3 is similarly smaller than the cylinder 22 and is engaged at the first end thereof within annular groove 52 in the plate 30, and at the other end thereof within an annular groove 54 in the plate Se.

The opposite end of the rod itl is secured to a third piston 5S by a holt d@ extending through both the piston 5S and a suitable seal 62. This piston 58 is of a reduced diameter as compared to the piston 38 and is received within a reduced diameter cylinder 64, the ends of which are suitably secured within annular grooves |66 in the plate 56 and 65S in the end plate 7i). It will be appreciated that these plates are maintained in clamping relationships to the aligned cylinder assemblies 16, l and 2t) by means of a plurality of peripherally spaced elongated tie rods 72, the ends of which are suitably threaded for the reception of nuts '7d thereon.

The chemical to be introduced into the liquid flowing through the feed line lil is stored in a suitable reservoir 76 which is in communication with the intermediate cylinder 5% `through a conduit 78 provided with a suitable checx valve d@ for preventing any bacldlow. Upon being expelled from the cylinder dll, in a manner which sh-all be pointed out presently, the chemical fiows through the conduit si., `provided with a check valve 84, into the feed line lil at a point past the check valve l2 Where it is mixed with the water llowing therethrough..

The movement of the pistons so as to effect an expelling of the selected chemicals from the cylinder Se results from an introduction of the water, upon an activation of the boiler pump, through the intake line 86 affording a communication between the feed line 1t? and the cylinder assembly 16 through the end plate 26, the pressure of the incoming fluid being suicient so as to overcome the return pressure Iflowing through the conduit 3S into the piston and cylinder assembly 2t).

This conduit 88 is intended to be in communication with the conventional .home water supply which is under substantially less pressure than the water within the conduit 86 under the influence of the boiler pump, and as such, offers little or no resistance to the movement .of the pistons while effecting the discharge of the chemicals. However, upon the boiler pump being deenergized, the pressure through the conduit 86 is removed and the pistons return to the opposite ends of the corresponding cylinders under lthe influence of the reduced pressure through the conduit SS, the ret-urn of the piston 38 .causing an inward flowing of the chemicals from the reservoir '76 through the conduit 78 so as to automatically prepare for a subsequent discharge of the chemicals upon the boiler pump again being energized.

it will be noted that the movement of the pistons, and consequently, the amount of chemicals discharged, can be regulated by an adjusting bolt 90 extending through the end plate 26 and being releasably maintained in position by a nut 92 for forming a stationary stop or abutment limiting the return movement of the pistou 32 as well as the pistons 38 and 58 interconnected for simultaneous movement therewith.

From the foregoing, it is considered to be readily apparent that a novel pressure operated chemical injector has been .defined wherein the pressure of the fluid from the boiler pump is introduced into a piston assembly normally maintained in an open position yby the pressure produced in the Water conventionally supplied which is less than the pressure produced by the boiler pump thereby allowing a closing or expelling movement of the pistons, with the pressure of the conventional water supply returning the pistons upon a deenergization of the boiler pump thus allowing for an automatic and periodic injection of a speoied amount of chemicals into a iiow of liquid.

The foregoing is considered as illustrative only of the pri-nciples of the invention. Further, since numerous modifications and changes will read-ily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. For use in combination with a boiler feed line having a periodic'flow, a pressure operated chemical injector comprising three axially aligned piston and cylinder assemblies .consisting of a first plate, an enlarged cylinder having one end secured thereto, the opposite end of the enlarged cylinder being secured to a second plate the opposite side of which has a first end of a second cylinder secured thereto, the opposite end of said second cylinder being secured to a third plate, a third cylinder having one end secured to the opposite side of the third plate and being secured at its opposite end to a fourth plate, a vpiston slidably received within said enlarged cylinder, a rod secured thereto and extending through said second plate and into engagement with a piston with-in said second cylinder and a second rod secured to a piston within the third cylinder, means introducing pressure from said feed line into said enlarged cylinder, said pistons movable simultaneously in response thereto, means communicating said third cylinder with a constant source of pressure less than the pressure in said 'feed line, and means in communication with said second cylinder for introducing and expelling a chemical in response to movement of the pistons.

2. The device of claim 1 including means for varying the amount of a chemical introduced into said second cylinder, this last mentioned means consisting of an elon- 3. The device of claim 1 wherein said means for introducing and expelling the chemical includes a chemical reservoir, conduit means communicating the reservoir with the second cylinder for the introduction of a chemical thereto, a check valve preventing back ow into the reservoir, conduit means communicating the second cylinder with the feed line for introducing the chemical thereto, and a check valve in said last-mentioned conduit means for preventing back flow from the feed line into Ithe second cylinder.

4. For use in combination with a boiler feed line hav- Ving a periodic ow, a pressure operated chemical injector comprising three axially aligned piston and cylinder assemblies consisting of a first plate, an enlarged cylinder having one end secured thereto, the opposite end of the enlarged cylinder being secured to a second plate the opposite side of which has a first end of a second .cylinderl secured thereto, the opposite end of said second cylinder being secured to a Lthird plate, a third cylinder having one end secured t-o the opposite side of Ithe third plate and being secured at its opposite end to a fourth plate,

a piston slidably received within said enlarged cylinder,

References Cited by the Examiner UNITED STATES PATENTS 549,479 11/95 Hall 137-5645 X 930,03 3 8/09 Bither.

Y 932,386 8/09 Gross 222-1292 1,094,116 4/ 14 Brown. 1,400,411 12/21 Booth.

1,736,803 11/29 Shields 137-5645 2,538,111 1/51 Luster 222-1292 2,574,756 11/51 Petseh 137-5645 M. CARY NELSON, Primary Examiner. 

1. FOR USE IN COMBINATION WITH A BOILER FEED LINE HAVING A PERIODIC FLOW, A PRESSURE OPERATED CHEMICAL INJECTOR COMPRISING THREE AXIALLY ALIGNED PISTON AND CYLINDER ASSEMBLIES CONSISTING OF A FIRST PLATE, AN ENLARGED CYLINDER HAVING ONE END SECURED THERETO, THE OPPOSITE END OF THE ENLARGED CYLINDER BEING SECURED TO A SECOND PLATE THE OPPOSITE SIDE OF WHICH HAS A FIRST END OF A SECOND CYLINDER SECURED THERETO, THE OPPOSITE END OF SAID SECOND CYLINDER BEING SECURED TO A THIRD PLATE, A THIRD CYLINDER HAVING ONE END SECURED TO THE OPPOSITE SIDE OF THE THIRD PLATE AND BEING SECURED AT ITS OPPOSITE END TO A FOURTH PLATE, A PISTON SLIDABLY RECEIVED WITHIN SAID ENLARGED CYLINDER, A ROD SECURED THERETO AND EXTENDING THROUGH SAID SECOND PLATE AND INTO ENGAGEMENT WITH A PISTON 